8.2 kB == 5.4 GB
Baobab false reported a folder to be 8.2kB big, while sorting it correctly as the biggest folder.
Nemo filemanager reports the true size correctly.
At the point of scan I was not modifying nor running any application that would access this folder(qemu) so it must be some weird arbitrary bug of baobab or potentially the file system api.
baobab version: 3.34.0-1
OS: Linux Mint 20.1 Cinnamon
File manager, Nemo: 4.8.6+ulyssa